This invention relates to a vibrating screen separator and, more particularly, to such a separator utilizing a device for tensioning a separation screen on a vibrating bed for separating solids of different sizes or for separating solids from a liquid.
A typical screen separator consists of an elongated, box-like, rigid bed, and a tensioned screen attached to, and extending across, the bed. The bed is vibrated as the material to be separated is introduced to the screen so that the liquid and/or relatively small sized material passes through the screen; while the relatively large sized material is maintained on the upper surface of the screen and conveyed to the discharge end of the bed for discharge. The bed can be vibrated by pneumatic, hydraulic, or rotary vibrators, in a conventional manner.
In these type arrangements, if the screen is not stretched correctly, i.e., if the proper tension is not applied to the screen, it will not properly separate the material discussed above and will often throw fluid and wear out quickly. Also, it is difficult to apply the proper tension to the screen, yet permit it to be easily removed for replacement.
Although several devices have evolved that are designed to apply tension to the screen, they suffer from several disadvantages. For example, they are difficult to use, take an inordinate amount of time, and are generally unsuitable to the hostile environment in which vibrating screen separators are often used. Also, some of these devices easily come out of adjustment and it is often difficult and time-consuming to replace them should they fail or wear out. Still further, many of these devices use a clamping force provided by air pressure, which is not always available, and use relatively small parts that can be lost, damaged or become out of adjustment.
Therefore, what is needed is a device for applying a relatively precise amount of tension to the screen of a screen separator that eliminates the problems set forth above.
An embodiment of the present invention, accordingly, is directed to a tensioning device for tensioning a screen relative to a wall of a separator in a manner so that the proper tension can be applied to the screen in a relatively quick manner and yet the screen can be easily removed and a new one installed.